The present invention relates to a gas turbine. The invention further relates to a method for controlling a gas turbine. The gas turbine includes at least one turbine, at least one compressor driven by the turbine and a combustion chamber arranged between the compressor and the turbine in the airflow path. The gas turbine is designed for compressing the gas in the compressor, heating the compressed gas in the combustion chamber and expansion of the heated gas in the turbine.
Gas turbines are used, for example, as engines for vehicles and aircraft, as prime movers for ships and for generating electricity in power stations. The present invention is primarily directed towards applications in which transient processes occur; that is to say, for dynamic applications. In such transient processes the load of the gas turbine varies relatively rapidly. One example of an application in which such transient processes are frequently performed is where the gas turbine is used to propel a vehicle or a vessel. These applications require acceleration and retardation on the part of the gas turbine. Still further, more stringent requirements for the low output of exhaust gas emissions call for precise control of the fuel supply even during transients.
In stationary operation the fuel supply is typically controlled by a feedback regulator reacting to the speed, pressure or temperature of the gas turbine. These quantities, however, are not stable in the case of rapid transients.
Traditionally, an air mass flow is calculated on the basis of other measurable quantities, such as gas generator speed or compressor pressure and the quantity of fuel delivered to the combustion chamber during transients is metered on the basis of the calculated air mass flow.
In many applications, and especially in the case of transient processes, great accuracy and speed are required. Such transients are furthermore usually associated with peak emissions since known solutions do not provide sufficiently rapid feedback control. It would therefore be desirable to achieve reduced exhaust emissions in the case of transients.